Trypanosomatids in Costa Rican Bats: First Molecular Evidence of the Leishmania (Viannia) guyanensis Complex and Evidence of a Broader Host Association for Trypanosoma minasense

Molecular data on wildlife trypanosomatids in Central America remain limited, constraining our understanding of host associations and sylvatic transmission cycles in the region. We characterized Leishmania and Trypanosoma infections in Costa Rican bats and assessed contemporary circulation of Trypanosoma minasense in howler monkeys within a comparative phylogenetic framework. Whole blood from 98 bats across 11 Costa Rican localities (2013–2014) was screened by PCR for Leishmania kDNA (120 bp), ITS-1 (~ 330 bp), and Trypanosoma 18 S SSU rRNA (nested PCR) with species-level identification based on sequence-confirmed amplicons. ITS-1 and 18 S amplicons were Sanger-sequenced and assigned by BLAST. For context, 18 S sequences from howler monkeys (Alouatta palliata) sampled in Costa Rica (2011–2025), including 20 animals from 2025, were included in phylogenetic analyses. Leishmania kDNA was detected in 4/98 bats (4.1%), but only one (Sturnira parvidens) yielded ITS-1 and clustered within the Leishmania (Viannia) guyanensis complex. Trypanosoma DNA was detected in 9/98 bats (9.2%): T. cruzi (n = 3), T. minasense (n = 3), and undetermined Trypanosoma spp. (n = 3). In 2025, 17/20 howler monkeys were PCR-positive for T. minasense; two were successfully sequenced and clustered within the Costa Rican T. minasense clade alongside bat-derived sequences. We report the first ITS-1- confirmed molecular evidence of the L. (V.) guyanensis complex in Costa Rican bats, supporting evidence of a broader host association and long-term local persistence of T. minasense across bats and primates.